These lab-quality hard plastic Petri dishes for sale make ideal egg-laying sites for dart frogs. They fit nicely under a typical coconut-style hide and are easy to clean and maintain. We have used these as water dishes for many small reptiles, and they work great for quarantine enclosures.
For small reptiles, you can trap them inside to view them easily and inspect wounds or otherwise hard-to-see areas like gecko feet and toes. There are a million and one uses for these Petri dishes and we always have some on hand in the gecko room, you never know when you might need one........or 50.